The invention relates to a pivoting bearing or a slewing ring, on installations where the subjected forces are significant.
The wind turbine field is particularly concerned.
In fact, proposing such a bearing for a blade of a wind turbine rotor hub is a purpose in itself.
Generally, there are already bearings liable to be subjected to extensive forces, the related bearing being interposed and fixed between a first structure and a second structure between which forces pass, via the bearing, at least one of these structures being able to turn with respect to the other, around the bearing rotational axis.
The bearing comprises:                a first and a second bearing race, a portion of the second bearing race extending around the first radially to said rotational axis,        and several sets of mobile members (or bodies), each interposed between the first and a second bearing races, annularly around said axis.        
On certain installations, the subjected forces may be very high both axially (rotational axis) and radially to this axis. The moments are also sometimes very important.
In the field of wind turbines, wind turbine blades are not only subjected to important forces in the axis of the/each blade (axial forces) but also to very important forces exerted radially to the blade axis and the rotor hub (forces thus called radial).
In this case, the aforementioned first and second structures may in particular be respectively a wind turbine rotor hub and a wind turbine blade, the blade being thus able to turn with respect to the hub around said bearing rotational axis.
The rotational speeds, the ever-increasing dimensions of wind turbines, the forces imposed by the wind, but also the forces pertaining to the pitch angle of the blades impose an ever-heightened resistance of the bearings.
In this respect, it is common that the bearings are able to pivot some ten degrees around their axis of elongation to promote the yield according to the strength of the wind.